1. Field of Invention
The invention relates to a control apparatus of a hybrid vehicle that uses an internal combustion engine and a motor/generator as a driving source.
2. Description of Related Art
FIG. 17 is a time chart showing one example of downshift disabling control on a congested road, and FIG. 18 is a time chart showing one example of control at the time of throttle actuation under downshift disabling control on a congested road.
Normally, on a congested road, a take-off/stop is repeated frequently and, concomitantly, an upshift/downshift is also repeated frequently. As such, a busy-shift state arises which deteriorates the quality of the ride. To prevent the occurrence of such busy shifting when the road is a congested road, congested road control that disables downshift to first or to second or lower and takes-off at a shift speed of second or higher at all times has been conventionally carried out.
However, when a driver feels a need to accelerate and actuates a throttle more than a specified amount, conventional congested road control on a congested road is canceled as shown in FIG. 18 (a time T1), and thereafter, normal shift control with downshift is executed. Therefore, for a case in which a congested state continues thereafter, busy shifting occurs.
Moreover, under congested road control as shown in FIG. 17, a vehicle speed is a low speed and, when taking-off, a vehicle takes-off at a high shift speed and an output on an internal combustion engine side is maintained in a low torque state. As such, when control is applied to a hybrid vehicle as it is, there are few opportunities for a motor/generator to perform a regenerating operation and charge of a battery. Therefore, the state of charge (SOC) decreases and a need for charging the battery when the vehicle stops occurs. A problem thus occurs in which the idle stop control for stopping the internal combustion engine when the vehicle stops, which is a characteristic of a hybrid vehicle, is difficult to execute.
Accordingly, the invention thus provides a control apparatus for a hybrid vehicle which does not cancel congested road control immediately even when a throttle is actuated under congested road control, and enables a charge (regeneration) of the battery even under congested road control.
The control apparatus for a hybrid vehicle with an internal combustion engine and a motor/generator connected to the internal combustion engine used as a driving source, an automatic transmission connected to the driving source, axles connected to the automatic transmission, and a sensor for detecting a running state of the vehicle according to a first exemplary aspect of the invention includes a controller. The controller judges whether the vehicle is running on a congested road based on an output from the sensor, causes a take-off from a first state where a gear ratio of the automatic transmission is large at a time of taking-off when running on the congested road, causes the take-off from a second state where the gear ratio of the automatic transmission is small at the time of taking-off when not running on the congested road and replenishes, by driving the motor/generator, a part of an under torque of the driving source created by taking-off from a state where the gear ratio of the automatic transmission is large, when a temporary high acceleration take-off request is made while a judgment of congested road running is maintained.
Thereby, at the time of temporary acceleration during congested running, the controller replenishes the under torque portion of the driving source using the drive of the motor/generator, so that even for a case in which a temporary high acceleration take-off request is made during congested road running, it is possible to perform a take-off operation without a sense of discomfort by maintaining the take-off operation from a state in which the gear ratio of the automatic transmission is large. Also, consequently, since there is no need to cancel congested road control, in congested road running thereafter, taking-off from a state in which the gear ratio of the automatic transmission is small is prevented, and busy shifting is prevented.
The hybrid vehicle according to a second exemplary aspect of the invention includes an internal combustion engine, a motor/generator connected to the internal combustion engine, wherein the internal combustion engine and the motor/generator are used as a driving source, an automatic transmission connected to the driving source, axles connected to the automatic transmission, a sensor for detecting a running state of the vehicle, and a controller. The controller judges whether the vehicle is running on a congested road based on an output from the sensor, causes the automatic transmission to perform normal shifting at a time of take-off by the internal combustion engine and consequently causes a regenerating operation by driving the motor/generator with extra torque produced from the internal combustion engine at the time of take-off, for a case in which when the vehicle is running on the congested road.
Thereby, for a case in which the controller judges that the vehicle is running on a congested road, it is possible at the time of take-off by the internal combustion engine to cause the automatic transmission to perform normal shifting and perform a regenerating operation by driving the motor/generator with extra torque produced from the internal combustion engine at the time of takeoff. It is possible to charge a battery, ensure a sufficient SOC, and effectively execute idle stop control, which is a characteristic of a hybrid vehicle.